Standard lifting devices for 55 gallon drums, including metal and plastic drums that are used for storing products such as dry goods and liquids, have numerous problems and limitations. For example, these prior art devices are designed for domestic warehouse applications and are not intended nor suitable for stevedoring operations aboard merchant cargo ships. Individual lifting mechanisms are often limited to fork lift type attachments that grip about the tops of single cylindrical drums. See U.S. Pat. No. 5,236,298 to Lehman which only has the capability of lifting one drum at a time with a fork lift. Devices such as the Lehman system also have potential slippage problems since this device does not grip about the indented portions of a drum body and instead tries to broadly grip about the largest outer diameter dimension when lifting.
Another problem with the single lift mechanism of Lehman is that the arcuate members are not fixably clamped in place during lifting and can separate during a lift causing a dram to fall and become damaged. Further, because the Lehman device must be attached to a forklift, that device is Snot a suitable piece of cargo handling equipment for stevedoring operations. Stevedoring operations require cargo handling equipment be attached to a spreader bar assembly for lifting drums from a cargo wharf to stowing aboard merchant cargo ships and also for later removing the cargo. Thus, devices such as Lehmans cannot work with stevedoring operations.
Thus, there is a need for an improved lift mechanism for lifting storage drums that avoid the problems associated with the prior art lifters referred to above.